The present invention relates to a filter apparatus which is provided with a stop valve and used for removing foreign substances.
Usually, a filter apparatus has a filter element for straining fluid so as to remove foreign substances therefrom. Because the efficiency of the filter element is reduced gradually by clogging of the filter, the filter element must be replaced with a new filter after a certain amount of fluid has been strained. When replacing the filter element, a cock separately provided in a pipe upstream of the filter apparatus must be closed so that the fluid does not leak from the filter apparatus.
In the conventional filter system described above, the filter apparatus and the cock are separately provided, and, therefore, it is troublesome to close the cock each time the filter element is replaced. If the valve is closed carelessly before the filter element replacement, the fluid will leak from the filter apparatus. Or, if the valve is left closed after the filter element replacement, the fluid will not be strained. Thus, the operation of closing and opening the cock is a disadvantage of the conventional filter apparatus.
It is therefore an object of the present invention to provide a filter apparatus which is provided with a stop valve and which allows for the easy replacement of the filter element.